Vuzix Corporation
FIXED FOCUS IMAGE LIGHT GUIDE WITH ZONED DIFFRACTION GRATINGS

Abstract:

An imaging apparatus for forming dual virtual images includes a planar waveguide, an in-coupling diffractive optic that directs a set of image-bearing light beams into the waveguide, and an out-coupling diffractive optic that directs the set of image-bearing light beams from the waveguide toward a viewer eyebox. The out-coupling diffractive optic includes an array of contiguous diffractive zones, each of which has a set of diffractive features having at least one of a common orientation and a common pitch. A succession of the zones along one dimension of the array have respective sets of diffractive features that progressively vary in at least one of orientation and pitch in a stepwise manner. The out-coupling diffractive optic is arranged together with the array of contiguous diffractive zones for forming a virtual image that is viewable from the eyebox at a near focus distance.